1. Field of the Invention
The present invention relates generally to water effects and, more particularly, to a method and apparatus for forming a projection screen using water, or other fluid, as the projection surface.
2. Description of the Related Art
Attractive water displays have been used for entertainment purposes for many years. These displays have taken the form of imaginative water fountains depicting a variety of pleasing shapes, often in conjunction with light, sound and other effects. In more recent times, water displays have included using water screens along with the variety of water fountains. The water screen can be further combined in various ways with still and moving pictures for an enhanced visual effect. Using projection water screens is particularly desirable for enhancing visual effects because it provides easy and fast set up and inexpensive and quick removal of the screen. Prior efforts have included U.S. Pat. No. 3,334,816 Shuzo Mizuno, Apparatus for Projecting an Image on a Jet of Water, 1967 which relates to apparatus for projecting on a water screen created by jets of water formed by rows of nozzles; U.S. Pat. No. 4,974,779 Araki, Screen Forming Apparatus and Method, 1990, and U.S. Pat. No. 5,067,653 Araki, Screen Forming Apparatus and Method, 1991, the Araki patents each having a device and method of forming a projection water screen by using a plurality of water spray nozzles disposed along a longitudinal pipe.
These prior art projection water screens have had a number of problems in trying to achieve the desired effects. In particular, the clarity of the image upon the water projection screens of the prior art devices was marginal. At the same time, the image brightness was adequate, but improvement was desirable. Moreover, maintainable and acceptable uniformity of the picture focus and illuminance across the projection screen was decidedly lacking.
For projection water screens, particularly those generated using multiple nozzles, surfaces of the projection water screens that are formed tend to be non-uniform due to the uneven flow of the fluid. At least one known prior art projection water screen, manufactured by Aquatique, and disclosed in EPO Patent Application No. 91401291.9, Publication No. 469936 Formhals, et al., is designed to have a pulsing exit pressure which causes concentric ripples radiating from the water nozzle to be formed in the water screen. Moreover, the turbulence vectors of the fluid flowing through the Aquatique nozzle cause consistent standing modulations in the distribution of the spray. These non-uniformities have resulted in projection water screens which have distortions and uneven brightness when still or moving images are projected upon them.
Another problem that has been experienced in using the prior an methods and nozzles is high noise levels. In large pan, the high noise levels are caused by the impact of portions of the fluid stream on the surface of the pool or body of water in which the nozzles are located. For certain prior art devices the noise level also increases due to the manner in which the fluid flow direction is abruptly changed; for instance, with the Aquatique device, the water direction is changed by directing high pressure water directly against a face plate causing substantial turbulence and loud noise. Noise levels experienced in these prior art devices are distractions which impair the ability of observers of the displayed images to clearly hear any accompanying audio track or effects and compromise show quality.
Yet another problem with prior art devices is seen in the overspray of fluid which contributes to the high noise levels described previously. This overspray also indicates that a significant percentage of the incoming fluid does not contribute to the formation of the projection screen and is therefore wasted.
Accordingly, there has existed a definite need for a fluid projection screen device and method which provides a projection screen which is uniform and provides for a clear and bright projection on it. There also exists a need for a fluid projection screen nozzle that operates at a low noise level so that it does not interfere with or detract from the display. There also exists the need for a nozzle that optimizes the utilization of the fluid flowing to produce the projection screen. The present invention satisfies these and other needs, and provides further related advantages.